Closed-loop conductance scanning tunneling spectroscopy: demonstrating the equivalence to the open-loop alternative

• Chris Hellenthal,
• Kai Sotthewes,
• Martin H. Siekman,
• E. Stefan Kooij and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2015, 6, 1116–1124, doi:10.3762/bjnano.6.113

• functions below 1 eV for a tungsten–platinum system, which they ascribed to poor vacuum conditions and contamination [32]. Similarly, the presence of water layers in the tunneling junction can also lead to lower apparent barrier heights [35][38]. However, the measurements presented in this article have been

Characterization of nanostructured ZnO thin films deposited through vacuum evaporation

• Jose Alberto Alvarado,
• Arturo Maldonado,
• Héctor Juarez,
• Mauricio Pacio and
• Rene Perez

Beilstein J. Nanotechnol. 2015, 6, 971–975, doi:10.3762/bjnano.6.100

• a tungsten boat. These powders are resistively heated and sublimated from the tungsten boat, placed 2 cm below and parallel to the substrate. The evaporation chamber has a pressure work of 4 × 10−4 Torr, and the current applied to the resistor is 42 A which resulted in a sufficiently high

Graphene on SiC(0001) inspected by dynamic atomic force microscopy at room temperature

• Mykola Telychko,
• Jan Berger,
• Zsolt Majzik,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2015, 6, 901–906, doi:10.3762/bjnano.6.93

• custom-built quartz-tuning fork sensor was used for the measurements. It had a main resonance frequency of 51294 Hz, a quality factor above 1000 and an estimated stiffness of ≈3800 N·m−1 [22]. The contact to the tungsten tip was made of a thin golden wire in order to avoid crosstalk with the deflection

• signal from the tuning fork piezo [22][23]. The tip has been treated by annealing to 1200 °C in contact with a hot tungsten filament. The simultaneous current and frequency shift measurements were done in constant height mode. A very slow tunneling current feedback was applied for compensation of the

In situ scanning tunneling microscopy study of Ca-modified rutile TiO₂(110) in bulk water

• Giulia Serrano,
• Beatrice Bonanni,
• Tomasz Kosmala,
• Marco Di Giovannantonio,
• Ulrike Diebold,
• Klaus Wandelt and
• Claudio Goletti

Beilstein J. Nanotechnol. 2015, 6, 438–443, doi:10.3762/bjnano.6.44

• in a compact “BEETLE”-type setup [20]. The STM housing was filled with Argon gas in order to ensure an inert atmosphere. Tungsten tips were used for the STM measurements. The tips were prepared by chemical etching (2 M KOH solution) and then coated with hot glue to minimize the faradaic current

Palladium nanoparticles anchored to anatase TiO₂ for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

• Kah Hon Leong,
• Hong Ye Chu,
• Shaliza Ibrahim and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2015, 6, 428–437, doi:10.3762/bjnano.6.43

• stirring by adding 1 g of the synthesized photocatalysts. A 500 W tungsten-halogen lamp was used as visible light source with a high pass UV light filter (FSQ-GG400, Newport Corp.). All experiments were carried out under identical conditions. The control experiment was carried out without photocatalyst to

Synthesis, characterization, monolayer assembly and 2D lanthanide coordination of a linear terphenyl-di(propiolonitrile) linker on Ag(111)

• Zhi Chen,
• Svetlana Klyatskaya,
• José I. Urgel,
• David Écija,
• Olaf Fuhr,
• Willi Auwärter,
• Johannes V. Barth and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 327–335, doi:10.3762/bjnano.6.31

• subsequent annealing at 723 K for 10 min. All STM images were taken in constant-current mode with an electrochemically etched tungsten tip. The supramolecular networks based on Gd–ligand coordination motifs described in the manuscript were fabricated in a two-step process: The molecular linkers NC–C≡C–Ph3–C

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• an arc discharge method resulting in a 1–3 nm inner diameter and a length of 200 nm [20]. An arc discharge was generated between a hexagonal BN (h-BN)-filled tungsten rod as an anode and a cooled copper electrode as cathode. The dark gray BNNTs were collected from the surface of the copper cathode

Morphology, structural properties and reducibility of size-selected CeO_2−x nanoparticle films

• Maria Chiara Spadaro,
• Sergio D’Addato,
• Gabriele Gasperi,
• Francesco Benedetti,
• Paola Luches,
• Vincenzo Grillo,
• Giovanni Bertoni and
• Sergio Valeri

Beilstein J. Nanotechnol. 2015, 6, 60–67, doi:10.3762/bjnano.6.7

• treatments were performed under an oxygen partial pressure of pO2 = 1·10−7 mbar. XPS measurements were performed using an Al Kα X-ray source and a hemispherical electron analyzer. The STM was operated at room temperature in constant current mode, by using electrochemically etched tungsten tips, degassed by

Si/Ge intermixing during Ge Stranski–Krastanov growth

• Alain Portavoce,
• Khalid Hoummada,
• Antoine Ronda,
• Dominique Mangelinck and
• Isabelle Berbezier

Beilstein J. Nanotechnol. 2014, 5, 2374–2382, doi:10.3762/bjnano.5.246

• , the sample is loaded into a dual beam FIB. Here, an additional protective Pt layer is deposited by FIB (Figure 1a) and a wedge is cut (Figure 1b) and lifted off using an in situ tungsten finger (Figure 1c). Next, several pieces (approximately 3 × 3 µm2) of the sample wedge are glued onto preshaped Si

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• -light irradiation [50]. b) Volume of hydrogen generated (VH2) under visible-light irradiation from a tungsten halogen lamp using Janus and core-shell Au50nm@TiO2 nanostructures, as well as amorphous TiO2 and bare gold particles [50]. c) Schematic illustration of plasmonic dye-sensitized solar cells

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• conventional sol–gel methods. The preparation of sol–gel silicates have been reported by several research groups [71][72]. Nevertheless, the use of chitosan is not limited to silicates and titanates. El Kadib et al. [73] demonstrated the use of chitosan microspheres as templates for vanadium, tungsten, and

• molybdenum oxide clusters, which were shown to be active as catalysts for selective alcohol oxidation. Similarly, Ganesan and Gedanken [74] had prepared tungsten(VI) oxide nanoparticles through the encapsulation of ammonium metatungstate on chitosan and the subsequent calcination. These particles showed a

• higher catalytic activity than bulk tungsten trioxide. Other materials, such as cobalt-Prussian blue nanoparticles [75], Zn–Al layered double hydroxide [76], hydroxyapatite [77], and calcium carbonate [78], were also prepared within, or in the presence of, chitosan gels. In a biological approach, calcium

Photodetectors based on carbon nanotubes deposited by using a spray technique on semi-insulating gallium arsenide

• Domenico Melisi,
• Maria Angela Nitti,
• Marco Valentini,
• Antonio Valentini,
• Teresa Ligonzo,
• Giuseppe De Pascali and
• Marianna Ambrico

Beilstein J. Nanotechnol. 2014, 5, 1999–2006, doi:10.3762/bjnano.5.208

• tungsten halogen lamp coupled with an Acton Reasearch Spectra Pro 300i monochromator. The photocurrent response as a function of the light intensity at given DC voltages and wavelengths were obtained by inserting neutral filters of various optical density on the light path towards the sample. A calibrated

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

• Sebastian Ahlberg,
• Alexandra Antonopulos,
• Jörg Diendorf,
• Ralf Dringen,
• Matthias Epple,
• Rebekka Flöck,
• Wolfgang Goedecke,
• Christina Graf,
• Nadine Haberl,
• Jens Helmlinger,
• Fabian Herzog,
• Frederike Heuer,
• Stephanie Hirn,
• Christian Johannes,
• Stefanie Kittler,
• Manfred Köller,
• Katrin Korn,
• Wolfgang G. Kreyling,
• Fritz Krombach,
• Jürgen Lademann,
• Kateryna Loza,
• Eva M. Luther,
• Marcelina Malissek,
• Martina C. Meinke,
• Daniel Nordmeyer,
• Anne Pailliart,
• Jörg Raabe,
• Fiorenza Rancan,
• Barbara Rothen-Rutishauser,
• Eckart Rühl,
• Carsten Schleh,
• Andreas Seibel,
• Christina Sengstock,
• Lennart Treuel,
• Annika Vogt,
• Katrin Weber and
• Reinhard Zellner

Beilstein J. Nanotechnol. 2014, 5, 1944–1965, doi:10.3762/bjnano.5.205

• hMSC in the presence of silver nanoparticles, the cells were sputtered with gold and subsequently with a tungsten layer to protect the cut surface from gallium contamination. Then the cross-sectional cutting area was analyzed by scanning electron microscopy (SEM). In different areas of silver

• concentration of silver nanoparticles (20 µg mL−1) for 24 h and single monocytes or lymphocytes were crosscut with FIB for intracellular imaging. Before FIB analysis, the cells were additionally coated with a thin layer of tungsten to protect the cut area from ion contamination. Similar to the results of light

Imaging the intracellular degradation of biodegradable polymer nanoparticles

• Anne-Kathrin Barthel,
• Martin Dass,
• Melanie Dröge,
• Jens-Michael Cramer,
• Daniela Baumann,
• Markus Urban,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2014, 5, 1905–1917, doi:10.3762/bjnano.5.201

• achieved and applied on a copper grid (3.05, 300 mesh, Agar Scientific, U.K.). The sections were observed in a Zeiss EM 912 transmission electron microscope with a tungsten filament at an acceleration voltage of 120 kV. Micrographs were taken via a Cantega Olympus slow scan CCD camera. UV−visible (UV−vis

Cathode lens spectromicroscopy: methodology and applications

• T. O. Menteş,
• G. Zamborlini,
• A. Sala and
• A. Locatelli

Beilstein J. Nanotechnol. 2014, 5, 1873–1886, doi:10.3762/bjnano.5.198

• obtained in dispersive plane operation, in which the exit plane of the energy analyzer is projected onto the detector. b) The (00) LEED spot profile from W(110). Tungsten 4f7/2 core level spectrum from a clean W(110) surface acquired in dispersive plane mode. The photon energy is 90 eV. The acquisition

Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials

• Ahmed Salama,
• Mike Neumann,
• Christina Günter and
• Andreas Taubert

Beilstein J. Nanotechnol. 2014, 5, 1553–1568, doi:10.3762/bjnano.5.167

• (Plano GmbH). Samples were cut at 1 mm/s at room temperature. Energy dispersive X-ray spectroscopy was done on a JEOL JSM 6510 SEM with tungsten hairpin filament (15 kV) and an Oxford INCAx-act SN detector with a resolution of 135 eV at 5.9 keV. Elemental analysis was done on a Vario EL III analyzer

Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties

• Priscilla Vasthi Quintana-Ramirez,
• Ma. Concepción Arenas-Arrocena,
• José Santos-Cruz,
• Marina Vega-González,
• Omar Martínez-Alvarez,
• Víctor Manuel Castaño-Meneses,
• Laura Susana Acosta-Torres and
• Javier de la Fuente-Hernández

Beilstein J. Nanotechnol. 2014, 5, 1542–1552, doi:10.3762/bjnano.5.166

• bulk semiconductor due to the quantum effects [6]. Among the non-toxic nanomaterials with a small energy band gap that are promising for photovoltaic devices are: iron sulfide (FeS2), tungsten sulfide (WS2) and copper sulfide (Cu2S) [7]. The last is a terrestrially abundant and interesting

Dry friction of microstructured polymer surfaces inspired by snake skin

• Martina J. Baum,
• Lars Heepe,
• Elena Fadeeva and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 1091–1103, doi:10.3762/bjnano.5.122

• way to modulate friction. They used groove-textured surfaces and performed frictional measurement on two different combinations of sphere and microstructure dimension. For the combination of a tungsten carbide sphere (diameter = 800 µm) and a microstructured silica surface (λ = 278 nm) the frictional

• coefficient parallel to the microstructure was higher, than in the perpendicular direction. The second investigated frictional pair was a steel ball (diameter = 800 µm) in contact with a microstructured tungsten carbide surface (λ = 220 µm). For this combination, the frictional coefficients in both directions

Nanoforging – Innovation in three-dimensional processing and shaping of nanoscaled structures

• Andreas Landefeld and
• Joachim Rösler

Beilstein J. Nanotechnol. 2014, 5, 1066–1070, doi:10.3762/bjnano.5.118

• . Conclusion: Compared with other forming techniques in the reduced scale, nanoforging represents a beneficial approach in forming freestanding metallic structures, due to its simplicity, and supplements other forming techniques. Keywords: forging; manipulation; nanoforging; plastic deformation; tungsten

• initial position. This principle allows fast and precise forging between both forming surfaces (video Supporting Information File 2). The bar stock was produced from a 0.5 mm drawn polycrystalline tungsten wire with a purity of 99.995%. Tungsten can be relatively easy machined electrochemically. It is

• cut on a tungsten bar stock exemplarily. ii) Forging between even surfaces is a free forming process also common in macroscopic forging processes. Basically there are two different kinds, the stretch forging and the spread forging. The grade of stretching and spreading can be influenced in the

Controlling mechanical properties of bio-inspired hydrogels by modulating nano-scale, inter-polymeric junctions

• Seonki Hong,
• Hyukjin Lee and
• Haeshin Lee

Beilstein J. Nanotechnol. 2014, 5, 887–894, doi:10.3762/bjnano.5.101

• buffered saline (10 mM, pH 4.0). The detector for the PEG standard was a reflective index detector (Shodex, RI-71), and a UV–vis spectrometer (Hewlett Packard HP 8453 spectrophotometer, 190 nm to 1100 nm, integration time 0.5 sec, interval 1 nm, Deuterium lamp for UV and tungsten lamp for vis) was used for

Visible light photooxidative performance of a high-nuclearity molecular bismuth vanadium oxide cluster

• Johannes Tucher and
• Carsten Streb

Beilstein J. Nanotechnol. 2014, 5, 711–716, doi:10.3762/bjnano.5.83

• ]. POMs are anionic metal oxide clusters formed primarily from early transition metals, mainly vanadium, molybdenum and tungsten [8]. The cluster assembly proceeds in solution by oligo-condensation reactions between reactive fragments, often by using templates to control the final cluster architecture [9

A visible-light-driven composite photocatalyst of TiO₂ nanotube arrays and graphene quantum dots

• Donald K. L. Chan,
• Po Ling Cheung and
• Jimmy C. Yu

Beilstein J. Nanotechnol. 2014, 5, 689–695, doi:10.3762/bjnano.5.81

• tungsten halogen lamp with a 400 nm cutoff filter. Photodegradation of MB was monitored by measuring the UV–vis absorption of the suspensions at regular time intervals. The suspension was centrifuged for 2 min to remove the photocatalyst before measurement. The peak absorbance of MB at 664 nm was used to

Calibration of quartz tuning fork spring constants for non-contact atomic force microscopy: direct mechanical measurements and simulations

• Jens Falter,
• Marvin Stiefermann,
• Gernot Langewisch,
• Philipp Schurig,
• Hendrik Hölscher,
• Harald Fuchs and
• André Schirmeisen

Beilstein J. Nanotechnol. 2014, 5, 507–516, doi:10.3762/bjnano.5.59

• for such a measurement is shown in Figure 2. In order to validate this measurement method we assembled a test sensor similar to the “qPlus” sensor setup. In the same way as in a “qPlus” sensor, a quartz tuning fork was glued onto a Macor body, and a tungsten wire with a diameter of dW-wire = 50 μm was

• directions, pushing (increasing mass on scale) or pulling (decreasing mass on scale). Please note that during a pull-experiment under the present conditions the relative elongation of the tungsten wire remains lower than 0.1% and is therefore neglected in the further analysis. A reference experiment was

• surface normal cannot be excluded. Unfortunately, the torsion caused by the non central fixation of the tungsten wire is increasing, when the wire is not perpendicular mounted to the tuning fork. Therefore we conducted further FEM simulations considering a possible wire axis tilt, with the results shown

Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

• Adam Sweetman and
• Andrew Stannard

Beilstein J. Nanotechnol. 2014, 5, 386–393, doi:10.3762/bjnano.5.45

• transferred into the scan head and left to cool before imaging. Commercial qPlus sensors from Omicron with electrochemically etched tungsten wire glued to one tine of the tuning fork were introduced into the scan head without any further preparation. We typically recorded resonant frequencies of f0 ≈ 25 kHz

En route to controlled catalytic CVD synthesis of densely packed and vertically aligned nitrogen-doped carbon nanotube arrays

• Slawomir Boncel,
• Sebastian W. Pattinson,
• Valérie Geiser,
• Milo S. P. Shaffer and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2014, 5, 219–233, doi:10.3762/bjnano.5.24

• Exeter Analytical CE-440 CHN Elemental Analyzer. A JEOL 6340F FEG SEM was used with an accelerating voltage of 5 kV. A secondary electron imaging (SEI) detector was used in all cases. TEM imaging of nanotube samples was performed on JEOL 200CX (tungsten filament, operated at 200 kV), JEOL 2000FX (LaB6